This project will study extended families from the largest "closed population" in North America (Chicoutimi-Saguenay-Lac St. Jean, Canada). They have identified 99 families from this unique population on the basis of each family having two siblings with both hypertension and dyslipidemia. One of the goals of this project is to obtain DNA, blood pressure, and anthropomorphic measurements in both parents and a total of 400 hypertensive and 400 normotensive 25-55 year old offspring in these families. These investigators also propose to complete extensive inpatient phenotyping in 200 of the younger (25-55) hypertensive and 200 normotensive siblings in these families. Regions of three selected quantitative trait loci found to be in linkage disequilibrium will be mapped with a family-based association haplotype analysis using single nucleotide polymorphisms (SNPs) as genetic markers coupled with a transmission disequilibrium test (TDT). The haplotype regions narrowed in the Canadian families within the area of linkage disequilibrium will be utilized in a case/control study to identify genes in African Americans of Milwaukee using SNPs in positional candidate genes. Both clinical projects will build upon broad based phenotyping data to determine if distinct clusters of traits can be identified to stratify hypertensive subjects for further genetic analysis.